Process of making extruded fibrous shapes



H. C. EGERTON.

PROCESS OF MAKING'EXTRUDED FIBROUS SHAPES.

APPLICATION FILED- APR. 20,1919. 7

1,370,800. Patented Mar. 8, 1921.

a wveutoz UNITED STATES PATENT OFFICE. 4

HENRY C. EGIlB'Il-YON, OI RIDGEWOOD, NEW JERSEY.

P300388 01' MAKING EXTRUDED I'IBROUB SHAPE. i

Specification of Letters Patent.

Patented Mar. 8, 1921.

Application filed April 26, 1919. Serial No. 89$,941.

To all whom it may concern:

Be it known that I, HENRY C. Eonn'ron, a

citizen of the United States, and resident of Ridgewood, Bergen county, New Jersey, have made a certain new and useful Invention Relatingto Processes of Making Extruded Fibrous Shapes, of which the following is a specification, taken in .connection with the accompanying drawing, which forms part of the same.

This invention relates especially to processes of making tubes, rods, sheets or other extruded shapes from material which may contain suitable pro ortions of incorporated cured phenolic con ensation cementing material, such as bakelite, condensite or redmanol compositions which may be present to the extent of thirty or sixty per cent. in the finished article, dependent, of course, on the portions of fibrous and inert coloring or other special material contained in these cementing compositions. Many suitable forms of fibrous material may be used for this purpose, such as cotton or' flax fiber in various forms. such, for example, as cotton batting or wadding which may sometimes be advantageously formed of special cotton fiber material which is preferably of substantially uniform length and for some such extruded articles may with advantage be of relatively short length fiber, such as a quarter of an inch long more or less. In some cases also suitable proportions of other fibrousmaterial may be used, such as Kraft paper pulp, rag stock, or the like, and in some cases it is advantageous to subject cotton or refined flax fiber to a beating process as in a paper pulp beater or refining engine I to reduce the fiber to the desired relatively to have the material be trolled heating conditions so as to form a pregnated or cemented-fibrous material may for this purpose be compressed under moderate heat to high pressure and this may advantageously be done under such conditions that a preliminary partial vacuum treatment of the material serves to withdraw at least a large part of the air therefrom before the compression thereof so that in this way blocks, sheets or strips of such compressed partly cured cemented fibrous material may substantially uniform fibrous extruded shape i e formed for feeding continuously or intermittently into the screw or other extruding presses. For many pur oses it is desirable ore extrusion cured or solidified to at least a very considerable extent so that it is in a substantially solidified but weldable or unitable condition -so that it may be united thoroughly and strongly under the high extrusion pressure and for this purpose suitable softening or uniting agents may be incorporated with the cementing-material, such as a few per cent. of anilin or other oily or softening uniting agent which makes it possible to unite severed portions of the material under heat at considerable pressure even after the curing has reached quite an advanced. stage.

The impregnated or cemented fibrous material with .or without such preliminary compression may be forced under proper heat and pressure through an extrusion die so as to form a continuous stream of highly compressed extruded material which may be heated and further cured. while in this condition and before the extrusion pressure is completely released so that a completely solidified or cured extruded article may be produced in this way, For many purposes a solid or hollow mandrel may be arranged within the extrusion die so as to form a hollow extruded article in connection, if desired with one or more cores, wires, or other members which may be fed into the same during the extrusion thereof. In some cases also either with or without such a metallic wire or core, impregnated fibrous material of this character may be extruded either inside or outside of a sheath of rubber, gutta percha, or other material which is desirable for some classes of electrical work.

The drawing shows in a somewhat diagrammatic way various forms of apparatus for carrying out this process, and

Figure 1 is a vertical section through an extruding press which may be used.

Fig. 2 is a perspective view of a blank or block of material for use in this connection; and

Fig. 3 is a sectional view through a curing chamber which may be used in some cases for subsequent curing of the extruded articles.

l/V here little or no inert coloring or other special material is used the fibrous composltion may comprise some forty to sixty er cent. of dried bakelite varnish or simi ar somewhat cured or combined phenolic condensation cementing material incorporated with sixt to forty per cent. of relatively short unii orm cotton fiber or other suitable fibrous material. This incorporation may be effected inany suitable wa so as to preferably efi'ect the substantial y uniform incorporation of the components. For some purposes beaten, clipped or otherwise prepared raw cotton fiber of good quality may be formed into sheets of wedding or batting and then sprayed or more or less immersed in warmed condition, preferably after inelos ing the same between thin fabric layers to facilitate handling in suitable bakelite varnish compositions which may advantageously in many ,cases contain relative] small proportions of the solvents used wit the phenolic condensation cementing ma terial. The solvent promotes the uniform penetration of the cementing material throughout the fibrous material with which it is incorporated and the individual fibers can thus be readily coated or united with the material so as to secure a more uniformly cemented fibrous composition which is advantageous for most extruded articles. In some cases instead of spraying or immersing sheets of such pure fibrous material the incorporation may be efiected in suitable mixing ap aratus, such as kneading machines of t e Werner-Pfleiderer type. UH? der these conditions the material may be somewhat warmed which minimizes the amount of solvent necessary and this may he still further minimized by using relatively uncured phenolic condensation cefibrous components in the menting material for incor oration with the rst instance, the preliminary curing changes being elfccted, if desired, by the heat used durin the incorporating or mixing rocesses. for some purposes relatively short fiber may be used to a greater or less extent and sulfate or Kraft pulp ma be used preferably after bein preliminari y heated to three or four hun red degrees and cooled at least to some extent before being incorporated with the phenolic condensation cementing material which seems to facilitate the incorporation of the henolic condensation material with the u timate wood fibers of this or other suitable wood pulp material. Of course when the thorough lncorporation of the components has been effected this cemented or impregnated fibrous material may be suitably dried under reduced pressure, if desired, so as to remove any volatile components or solvent elements and then formed into sheets, rods, blocks or other blanks for use in this process.

It is usually advantageous to remove the entrained air from such cemented fibrous material and also in most cases to press and partly cure the same before the extriuliug operation, and for this purpose the cemented or impregnated fibrous material may be compressed preferably after a vacuum treatment to remove the air so as to form compressed blanks of suitable shape and size so that, for instance, a cylindrical blank 22 may be formed of suitable fibrous material of this character and subjected to the desired curing treatment before or after being compressed into this form so that the material approaches sutlieientlyto the solid moderately or completely cured condition, so that a comparatively short heat treatment is sufiicient to give the desired strength and rigidity to the extruded article either during or after the extruding step. Fig. 1 shows a form of plunger extruding press which may be used for making such extruded fibrous shapes or articles and the press body 1 may be formed with a cylindrical bore 2 of such size as to receive the compressed blanks 22 of partly cured fibrous material which may then be compressed by the hydraulic or other plunger 3 fitting fairly tightly within this bore or chamber. The extrusion chamber may be formed with a shaped discharge end 27 having a more or less tapering threat 5 of such size and shape as corresponds to the article or extruded sha e to be formed and this may be conveniently effected by using a removable die 4 which may be screwed into the body or chamber of the press, so that the highly compressed material may be forced into the contracting throat and form a stream of extruded material, such as 24, of the desired size and shape. It is of course under- (lf course till Hill

die and at a stood that in some cases where a tubular or other hollow article is desired an internal mandrel 9 may be used within the die and this may be formed on a removable support a 7 having a tapered portion 8 cooperatmg with the throat of the extrusion d1e and a threaded end 6 on this membermay be screwed into the opposite end of the press body so that the mandrel cooperates with the extruding passage in the die. Of course the mandrel or extruding die passage or both may be iven special sha es to form correspondingl y shaped extrued sections and in this way square sectioned tubes or corrugated tubes or gear pinions or other irregular shapes may be conveniently and accurately formed of such fibrous material which by varying the proportions and charactor of the fibrous material contained may be given corresponding strength, toughness and rigidity.

It is desirable where the cemented fibrous material is in partly cured condition when it is supplied to the extrusion press to heat it to at least a moderate degree before it is forced throu 11 the throat of the extrusion %out the time the material enters this extrusion passage it may advantageously be heated to a considerably greater temperature, such as 300 to 350 Fahrenheit, or in some cases to still higher temperatures which effect a correspondingly quicker and more complete cementing and iuring action on the fibrous material especially under the high extrusion pressure used which may bea number of t ousand pounds per square inch in many cases.

This heatin of the extruded material may be effected E having the extrudin die 10 of considerab e length and an extru ing passage a number of feet long may advantageously be used where a considerable curin action is to be effected during this art 0 the process. By the use of sultable eating elements around or in connection with the extruding die, such, for example, as the steam or other heating pipes 15 which may have the connections 16, 17, one or more feet of this extruding passage may be heated to quite high temperatures, such as 400 to 500 Fahrenheit or more, although charring and undesirable transformation of the material should of course be avoided; such high curing heats effectively cure, cement and unite the fibrous material durin this part of the process while it is still sub ected to considerable pressure; Where such relativoly high temperatures are used it is usually desirable to at least partly cool the heat-- ed extruded material before the extrusion pressure is completely released and for this purpose the discharge end of the extrusion passage may be cooled by any suitable means, such, for example, as brine or other cooling pipes 18, arranged or coiled around of the passage or by arranging suitable any desired length of the discharge and of the extrusion passage and havin inlet and outlet connections 19, 20. Suita le heat insulating material, such as 26, may of course be arranged around the extrusion so as to prevent heat transfer therefrom.

The extruded article 24 may be kept under suitable longitudinal compression during the extrusion process by regulatin its movement past the discharge end 0 the extrusion die or passa e and this may be effected by regulating t e size of this art ra plates ormembers, such as 12, which mag lave pro'ections or portions fittin within the annularrecess 11 in the end 0 the extrusion die. conical compression member 13 which may have a cylindrical threaded portion 14 00- operating with these drag members 12 their dlscharge ends may be forcibly compressed or brought together so as to frictionall engage the extruded article 24 to a sufficient extent to prevent undesirable release of pressure thereon and prevent development of as or ex ansion action when relatively hig curing eats'are used at various parts of thei'extrusion passa e or process. Of course, when the hydrau ic or other plun er 3 nears the bottom of the extrusion cham er it may be quickly withdrawn and another blank or block 22 of the compressed partly cured fibrous material such as is shown in Fig. 2 may be inserted-in the chamber and com ressed beneath the plunger so as to be re ually forced out through the extrusion ie when the other material 23 has been discharged. By having the cemented or impregnated fibrous material in artly or substantially cured cemented con ition when it is supplied to the extrusion press of the plun er or continuous screw type it is sufliciently consistent so that under the moderate temperatures used in the main extrusion chamber as determined by the heating jets or other heating means 21 the incorporated phenolic condensation cementing material 088 fibrous material to an undesirable extent, especially where relatively short uniform fiber is used. Thus suflicient uniformity of character of the extruded material may be secured for many types of insulating or other articles which may be readily and conveniently formed of accurate cross-section and polished surfaces, if desired.

It is sometimes desirable. tosubsequently cure the extruded articles in continuous lengths or separated pieces and for this purpose they may be cured at the desired temperature in air or steam chambers under pressure in some cases orv by immersing them in oil or waxy heating mediums by which suita le waxy or other coatings may be conveniently applied thereto which is passage By the-use of a tapered or not tend to flow through or past the desirable for some forms of electrical bushings or insulating tubes of this general character. Fig. 3 shows a )ressure curing chamber which may be used in connection with an extrusion press for roducing lengths of suclrfibrous material. he chamber 30 may be formed of strong sheet steel or other material and may have an inlet end or portion 33 having a threaded connection 32 with the end 31 of the extrusion die which under these conditions need not always be of such length or heated and cooled to such an extent as described in connection with the Fig. l extrusion apparatus. The extruded article or shape 24 ma thus be delivered into the chamber 30 which may be heated to the desired curing temperature and kept under considerable pressure by steam or other heating fluid which may be supplied through the connection 45 formed, if desired, in the end plate 43 removably secured to the chamber as by the bolts 44. In some cases it is desirable to successivel cut off lengths of the extruded material as it enters the chamber and forthis urpose a cutting device 0 any suitable c aracter may be installed inconnection with orinside the chamber so as to cut off any suitable lengths 25 of the extruded rod, tube, strip or shape which may then be further cured Within the chamber before the extrusion pressure has been reduced to atmos herio pressure, A form of cutter which is diagrammatically indicated in this connection may comprise the steel disk 36 formed with a series of cuttin apertures 37 in its periphery and revolu ly mounted on a stem 38 projectingthrough a packed or other gland in the end of the curing chamber. A handle or lever 39'on this stem may be used to quickly swing the cutting disk across the advancing extruded article so that a narrow portion of the disk cuts through the extruded material before another adjacent opening is reached in the disk which allOWS another length of material to enter the chamber and be out off in turn. The length of the material cut off in this way may be controlled in any suitable manner either by visually observing the length of material within the chamber and manually operating the cutting device in accordance therewith or by electrical or other automatic means which may be used in this connection. As indicated an observation opening 42 may be formed in the chamber and covered by a glass or other transparent member 40 in the frame 41. When sufficient material has accumulated in such a curing chamber it may be removed from the press or the material taken out of the chamber. It is, however,

- desirable in some cases to continue the ourstance when a new disk or blank of fibrous material is being inserted in the extruding chamber of the press the entrance portion 33 of the curing chamber may be closed as by the cutting or gate valve 35 which may be forced down within its casing 34 so as to sever the partial length of material 24 and then hermetically seal the curing chamher which may then be released from the die 31 with which it may have any suitable screw connection and another similar curing chamber applied to receive the 'extraded lengths which are produced by the press as soon as the recharging thereof has een completed preferably within a very short time to minimize local over-curing of .the material Withinthe heated extrusion passages, etc. It is not, however, necessary in all cases to completely cure the extruded material and it is advantageous for some purposes to have the extruded and shaped material left in such part-1y cured condition that the extruded tubes, rods or other articles may be heated and bent or otherwise reshaped after being extruded or in connection with the extrusion rocess which facilitates their use in manu acturing certain classes of chemical or electrical apparatus or for other purposes. After such bending, shaping or umting treatment the partly cured material may then be still further or more completely cured by suitable heat under pressure, if desired, so as to give the completely shaped articles greater strength and security of union in various parts. While for electrical insulating purposes it is usually desirable to have relatively pure mixtures of cotton or other suitable cellulose fiber and bakelite or other phenolic condensation cementing material, yet for some purposes more or less coloring or inert filling or other special material may be used in such extruding compositions to more or less replace at least part of the fibrous material used and'the material preferably after being properly incorporated and preferably. more or less compressed and partly cured may be extruded into the desired shape and simultaneously cured to a greater or less extent in the manner de- 115 scribed. In some cases fibrous or other asbestos may be used instead of the cellulose fiber referred to and for some special purposes. fibrous material may be substantially omitted or replaced by powdered or other 120 inert filling or coloring materials to form extruding compositions containing considerable proportions, such as 30 to 60 per cent. more or less of phenolic condensation cementing material. 125

This invention has been described in connection with a number of illustrative embodiments, forms, materials, proportions, conditions of temperature, pressure, time and other treatment and nature and order 130 of steps, to the details of which disclosure the invention is not of course to be limited, since what is claimed as new and "what is desired. to be secured by Letters Patent is set forth in the appended claims:

1. The process of forming tubes or other extruded shaped lengths of fibrous material containing incorporated curedphenoliccondensation cementing material which comprises thoroughl incorporating, with relatively short uni orm length fi rous material phenolic condensation cementing material to the extent of at least thirty per cent. by weight thereof toform cement fibrous material, compressing said fibrous material to remove air therefrom and forming compressed blanks thereof and artly curin such cemented fibrous materi heating an forcing the same through an extruding die havin a central mandrel to form a hollow extruded acticle around said mandrel, heating such shaped extruded hollow article and cooling the same while controlling itslongitudinal movement and completing the curing of the phenolic condensation cementing material in the extruded article.

2. The process of forming tubes or other extruded shaped lengths of fibrous material containing incorporated cured phenolic condensation cementing material which comprises incorporating with fibrous material phenolic condensation cementing materlal to the extent of at least thirty per cent. b weight to form cemented fibrous materia, compressing said fibrous material to remove air therefrom and forming compressed blanks thereof and part1 during such cemented fibrous material, heating and forcing the same through an extruding die having a central mandrel to form a hollow extruded article around said mandrel, heatin such shaped extruded hollow article an cooling the same while controlling its longitudinal movement.

3. The process of forming extruded shaped lengths of fibrous material containing incorporated cured henolic condensation cementing materia wh1ch comprlses incorporating with fibrous material henolic condensation cementing materia to the extent of at least thirty per cent. by weight thereof to form cemented fibrous material, compressing said fibrous material to remove air therefrom andforming compressed blanks thereof and artly curing such cemented fibrous material, heat ng and forcing the same through an extruding die having a central mandrel to form extruded article, heatin such shaped extruded article and coo ing the same while controlling its longitudinal movement.

4. The process of forming rods, tubes or other extruded shaped lengths of fibrous 4 material containing incorporated cured henolic condensation cementing material w ich material, part1 comprises thoroughly incorporating relative y short length fibrous material with henoliccondensationcementingmaterial'to orm cemented fibrous material, compressing said fibrous material to remove 8.11 therefrom other extruded shaped lengths of fibrous material containin incorporated partly cured phenolic con ensation cementing material which comprises thoroughly incorporating fibrous material with phenolic condensation cementing material to form cemented fibrous material, partly curing such cemented fibrous material, -heating and forcing the same through an extruding die having a central mandrel to form a hollow extruded article around said mandrel.

6. The process of formin rods or other extruded shaped lengths of fibrous material containing incorporated partly cured phenolic condensation cementing material which comprises thoroughl incor crating fibrous material with pheno ic con ensation cementing material to form cemented fibrous curing, such cemented fibrous materia, heating and forcing the same through anextruding die to form an extruded article.

7. The process of forming extruded shaped lengths of fibrous material containing incorporated cured phenolic condensation cementing material which comprises incorporating with fibrous material phenolic condensation cementing material to the extent of at least forty per cent. by weight thereof to form impregnated fibrous material, partly curin such fibrous material, heating and extru ing the same, a shaped extruded article, heating said shaped extruded article and cooling the same while controllin substantia 1y comp eting the curing of the phenolic condensation cementing material inthe extruded article.

8. The process of forming extruded shaped lengths of fibrous material containing incorporated cured phenolic condensation cementing material which comprises incorporating with fibrous material henolic condensation cementing materia to form impregnated fibrous material, partly curin such fibrous material, heating and extru ing the same, a shaped extruded article, heating said shaped extruded article its lon itudinal movement and while controlling its longitudinal movement and substantially completing the curmg of the henolic condensation cementing material 1n the extruded article.

9. The process of forming extruded fibrous articles containing partly cured phenolic condensation cementing material WlllOll comprises forming compressed cemented fibrous material containing thirty to sixty per cent. by weight of partly cured incorporated henolic condensation cementing material, Eeatin and extruding such compressed cementeg fibrous material and cooling the resulting extruded article before its complete release from pressure.

10. The rocess of forming extruded fibrous artic es containing partly cured henolic condensation cementing material w ich comprises forming compressed fibrous material containing partly cured incorporated phenolic condensation cementing material, heating and extruding such compressed cemented fibrous material and cooling the resulting extruded article before its complete release from pressure.

11. The process of forming extruded fibrous articles containing partly cured phenolic condensation cementing material which comprises forming compressed fibrous material containin partly cured incorporated phenolic condensation cementing material, heating and extruding such compressed cemented fibrous material.

12. The process of forming extruded articles of fibrous material containing partly cured phenolic condensation cementing material which comprises forming short lengthfiber material containing over thirty per cent. by weight of party cured phenolic condensation cementing material, heating and extruding such fiber material and cooling the resulting extruded article before its release.

13. The process of forming extruded articles of fibrous material containing partly cured phenolic condensation cementing material which comprises forming fiber material containin partly cured phenolic condensation cementing material heating and extruding such fiber material and cooling the resulting extruded article before its release.

14. The process of forming extruded articles of fibrous material containing partly cured phenolic condensation cementing material which comprises forming compressed cemented fibrous material containin incorporated partly cured weldable pheno ic condensation cementing material, heatin and extruding such compressed cemented fibrous material and cooling the resulting extruded 7 article before its release.

15. The process of forming extruded articles of fibrous material containing partly cured phenolic condensation cementing material which comprises forming cemented fibrous material containing incor orated cured weldable henolic condensation cementing materia, heating and extrudin such compressed cemented fibrous materia. 16. The process of formin tubes or other extruded s aped lengths of brous material comprising incorporated cured phenolic condensation cementing material and fibrous material, which comprises com ressing such fibrous material to remove airt erefrom and forming compressed blanks thereof and partly curing such material, heating and forcing such material throu h an extrudin die having an inner mandre to form a ho low extruded article around said mandrel heating said shaped extruded article and coolin the same while controlling its longitudina movement and completing the curing of the phenolic condensation cementing material in the extruded article.

17. The rocess of forming tubes or other extruded s a ed lengths comprising incorporated cure phenolic condensation cementmg material, which comprises compressin such material to remove air therefrom an forming compressed blanks thereof and partly curing such material, heating and forcing such material through an extrudin die having an inner mandrel to form a ho low extruded article around said mandrel heating said shaped extruded article and cooling the same while controlling its longitudinal movement.

18. The process of forming extruded shaped len ths comprising incorporated cured pheno lic condensation cementing material, which comprises compressing such material and forming compressed blanks thereof and partly curing such material, heating and forcing such material through an extruding die to form an extruded article, heating said shaped extruded article and coolin the same while controlling its longitudina movement.

19. The process of forming rods, tubes or other extruded shaped lengths of material comprising at least thirty per cent. of incorporated cured phenolic condensation cementing material, which comprises forming and partly curing such material, hcatin such material and forcing the same throug an extruding die having an inner mandrel to form a hollow extruded article around said mandrel, heatin said shaped extruded article and cooling t e same While controlling its longitudinal movement.

20. The process of forming extruded shaped lengths of material comprising at least thirty per cent. of incorporated cured phenolic condensation cementing material, which comprises forming and partly curin such material, heating such material an forcing the same through an extruding die to form an extruded article, heating said 1 shaped extruded article and cooling the which comprises forming and partly curin same while controlling its longitudinal such matenal, forcing such material throu? movement. 1 anextrudin die to form an extruded artic e, 10

21. The process of forming extruded heating sai shaped extruded article and .5 shaped lengths of material cdmprising at further curing the same before releasing the least thirty per cent. of incorporated phesame from pressure. nolic condensation cementing material, HENRY C. EGERTON. 

